1,4-Disubstituted diacetyline polymer and process for producing the same

ABSTRACT

A 1,4-di-substituted diacetylene polymer that is soluble in organic solvent, is composed of a repeating unit represented by the general formula ═CR—C≡C—CR′═ (wherein, R and R′ represent identical or different monovalent organic substituents), and has an average degree of polymerization of 4 to 200 and a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight corresponding to said average degree of polymerization (Mn) of 1.1 to 5.0, and a process for producing the 1,4-di-substituted diacetylene polymer by irradiating a solution of the soluble 1,4-di-substituted diacetylene polymer with laser light having a wavelength within the range of 250 to 1,200 nm, and preferably 550 to 900 nm, to cause a photodegradation reaction of said polymer, or heating a solution of the soluble 1,4-di-substituted diacetylene polymer to a temperature of 100 to 300° C. to cause thermal degradation of said polymer; and 1,4-di-substituted diacetylene polymers for which the average degree of polymerization and molecular weight distribution are controlled to within predetermined ranges, a production process that enables that control, useful composite compositions based on the 1,4-di-substituted diacetylene polymers, and constitutions of materials in which said composite compositions are used.

TECHNICAL FIELD

The present invention relates to 1,4-di-substituted diacetylene polymersrealized by controlling the average degree of polymerization, numberaverage molecular weight corresponding to said average degree ofpolymerization, and molecular weight distribution based on the weightaverage molecular weight, and their production process.

BACKGROUND OF THE INVENTION

Polymers (referred to as polydiacetylenes) obtained by solid-statepolymerization of 1,4-di-substituted diacetylene monomers (R—C≡C—C≡C—R′:wherein, R and R′ represent identical or different monovalent organicsubstituents) have a main chain structure consisting of a repeating unitin the form of ═CR—C≡C—CR′═, and form macromolecules having a molecularweight on the order of several million.

Although polydiacetylenes are characterized by the main chain having afully conjugated, extended chain structure, they have also attractedmuch a tension from the view point of optically active materials, suchas an extremely large third order non-linear optical susceptibility[χ⁽³⁾=10⁻⁹ to 10⁻¹⁰ esu, C. Sauteret et al., Phys. Rev. Lett., 36, 956(1976)], and photo-induced phase transition phenomena [S. Koshihara etal., J. Chem. Phys., 92, 7581 (1990)] based on excitons of theconjugated π-electron system of the main chain.

However, the majority of common polydiacetylenes are insoluble insolvent due to the rigidity of the main chains, and since they alsodecompose without melting when heated, it has been essentiallyimpossible to measure their molecular weight, molecular weightdistribution and other solution properties.

In contrast, in the case of 1,4-di-substituted diacetylene polymerscontaining such long side chains as flexible and easily solvatedsubstituents in the form of R and R′ in the aforementioned repeatingunit (for example, in the case in which R and R′ represent(CH₂)₄OCONHCH₂COOC₂H₅), molecular weight, molecular weight distributionand other solution properties can be measured on an exceptional case dueto being soluble in polar solvents.

However, there has of yet been no research nor development conductedwith an intention to control the average degree of polymerization, andthe molecular weight distribution even for those solublepolydiacetylenes, thus no sample of 1,4-di-substituted diacetylenepolymers based on said control is near at hand.

One of the technical background factors behind these circumstances is asfollows. In the case of polyaddition reactions of common olefinmonomers, molecular weight of polymers can be controlled by the amountof the initiator against the monomer, and such a control is alsopossible for polycondensation reaction of polyesters, polyamides and soforth by changing the relative ratio of the reactants.

In contrast, polymerization of diacetylene compounds is quite unique inthe sense that polymerization initiates without any common initiators,but by the external stimulation such as high energy beams, UV-light,shear stress, thermal treatment and so forth.

The cause of this difficulty in controlling molecular weight andmolecular weight distribution is that, in the case of solid phasepolymerization of diacetylene compounds, in addition to being unable tospecify the concentration of the active sites of polymerization, sinceno initiator is added on purpose. In addition, propagation proceeds veryrapidly via chain reaction, high molecular weight polymers are presentin the unreacted monomer phase in the solid solution state even in thevery early stages of the reaction, thereby making it impossible toisolate low molecular weight oligomers in a good yield.

This is also the case even for polydiacetylenes having molecular weightsranging from ten thousand to several million.

Incidentally, although the relationship between polymer conversion rateof diacetylene compound [substituent R═R′═(CH₂)₄OSO₂C₆H₄CH₃] andmolecular weight has been described (G. Wenz et al., Mol. Cryst. Liq.Cryst. 96, 99 (1983)), as shown in FIG. 1, in the state of a conversionrate of 0.2%, namely when 99.8% of the monomer still remains, themolecular weight of the formed polymer is already within the range of10,000 to 100,000, and at a conversion rate of 4.5%, the molecularweight covers a continuous, wide distribution from several ten thousandsto several million.

Moreover, at a conversion rate of 42% or higher, the product consistsprimarily of only polymers having high molecular weights ranging fromseveral hundred thousands to several million.

On the basis of such experimental results, the selective and efficientpreparation of diacetylene polymers in which molecular weight andmolecular weight distribution are controlled has been judged to beextremely difficult during the course of the polymerization reactionwith respect to polydiacetylenes.

On the other hand, in the aspect of practical use, materials made frompolydiacetylenes have been evaluated as being conjugated polymers havingextremely large third order non-linear optical susceptibility as well asother superior characteristics.

However, since polydiacetylenes happen to cause light scattering due tothe phase separation in a matrix material based on the rigidity of themain chains, improvement of their processability has been desired.

In consideration of the circumstances surrounding polydiacetylenes asdescribed above, the object of the present invention is to provide1,4-di-substituted diacetylene polymers by controlling the averagedegree of polymerization and molecular weight distribution withinpredetermined ranges, a production process that allows this control,useful compositions based on the 1,4-di-substituted diacetylenepolymers, and constitutions of a member that uses said compositions.

DISCLOSURE OF THE INVENTION

The compound according to the present invention having for its object tosolve the aforementioned problems is composed of 1,4-di-substituteddiacetylene polymer that is soluble in an organic solvent, composed of arepeating unit represented by the general formula ═CR—C≡C—CR′═(wherein Rand R′ represent identical or different monovalent organicsubstituents), and have an average degree of polymerization of 4 to 200and a ratio (Mw/Mn) of weight average molecular weight (Mw) to numberaverage molecular weight corresponding to said average degree ofpolymerization (Mn) of 1.1 to 5.0.

The substituents R and R′ are preferably the monovalent organic groupsindicated below:

-   -   (CH₂)_(m)OCONHCH₂COOC_(n)H_(2n+1) (wherein m represents an        integer within the range of 3 to 6, and n represents an integer        within the range of 1 to 10),    -   (CH₂)_(m)CONHCH₂COOC_(n)H_(2n+1) (wherein m represents an        integer within the range of 3 to 6, and n represents an integer        within the range of 1 to 10),    -   (CH₂)_(m)OSO₂C₆H₄CH₃ (wherein m represents an integer within the        range of 3 to 6), and    -   (CH₂)_(m)OCONHCH₂CONHC_(n)H_(2n+1) (wherein m represents an        integer within the range of 3 to 6, and n represents an integer        within the range of 1 to 10).

The aforementioned 1,4-di-substituted diacetylene polymers according tothe present invention (referred to as the “present polymer”) can beproduced by:

-   -   (1) irradiating a solution of soluble 1,4-di-substituted        diacetylene polymer with laser light having a wavelength within        the range of 250 to 1,200 nm, and preferably 550 to 900 nm, to        cause a photodegradation reaction of said polymer, or    -   (2) heating a solution of soluble 1,4-di-substituted diacetylene        polymer to a temperature of 100 to 300° C. to cause thermal        degradation of said polymer.

Namely, polymers can be produced having an average degree ofpolymerization within the range of 4 to 200, and in which the ratio(Mw/Mn) of weight average molecular weight (Mw) to number averagemolecular weight (Mn) can be controlled to within the range of 1.1 to5.0 based on photodegradation or thermal degradation of1,4-di-substituted diacetylene polymer as described in theaforementioned methods of (1) or (2).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the relationship between polymer conversion rate andmolecular weight distribution during the course of solid phasepolymerization of polydiacetylene.

FIG. 2 shows the relationship between GPC retention time and molecularweight prepared using mono-dispersed polystyrene standard samples.

FIG. 3 shows changes in the GPC (gel permeation chromatography) curvesof a diacetylene polymer versus the irradiation time of laser light(wherein the excitation wavelength is 775 nm, the intensity is 40 mW andthe detecting wavelength is 350 nm).

FIG. 4 shows the molecular weight distribution of polydiacetylene priorto degradation.

FIG. 5 shows the molecular weight distribution of a reaction productresulting from irradiation with laser light (wherein the wavelength is775 nm, the intensity is 300 mW, and the irradiation time is 1 minute).

FIG. 6 shows the molecular weight distribution of a reaction productresulting from irradiation with laser light (wherein the wavelength is775 nm, the intensity is 300 mW, and the irradiation time is 10minutes).

FIG. 7 shows the molecular weight distribution of a reaction productresulting from irradiation with laser light (wherein the wavelength is800 nm, the intensity is 15 mW, and the irradiation time is 60 minutes).

FIG. 8 shows the molecular weight distribution of a reaction productresulting from irradiation with laser light (wherein the wavelength is900 nm, the intensity is 15 mW, and the irradiation time is 60 minutes).

FIG. 9 shows the molecular weight distribution of a reaction productresulting from irradiation with laser light (wherein the wavelength is387.5 nm, the intensity is 90 mW, and the irradiation time is 60minutes).

FIG. 10 shows the molecular weight distribution of a reaction productfollowing heat treatment for 30 minutes at 150° C.

FIG. 11 shows the molecular weight distribution of a reaction productfollowing heat treatment for 60 minutes at 150° C.

BEST MODE FOR CARRYING OUT THE INVENTION

Specific mode for carrying out the production according to theaforementioned (1) and (2) are as shown below.

(1) Providing of 1,4-di-substituted diacetylene monomer: Crystals ofmonomers of 1,4-di-substituted diacetylene are provided in which theorganic substituent groups bonded to positions 1 and 4 are monovalentorganic groups so as to enable preparation of the polymer described inclaim 1.

(2) Production of 1,4-di-substituted diacetylene polymers: The crystalsof 1,4-di-substituted diacetylenes described in (1) are eitherirradiated at room temperature with 30 to 50 Mrad of gamma rays fromcobalt 60 as the radiation source, or the aforementioned monomercrystals are held at a temperature 5 to 10 degrees lower than themelting point, to form a 1,4-di-substituted diacetylene polymer at aconversion rate of 95% and having an average degree of polymerization of2,000 or more (and in most cases, the corresponding number averagemolecular weight is 1 million or more).

At that time, the remaining monomers can be extracted with acetonefollowed by vacuum drying in a desiccator to obtain a sample from the1,4-di-substituted diacetylene polymers.

(3) Preparation of 1,4-di-substituted diacetylene polymer solution: The1,4-di-substituted diacetylene polymer obtained according to the processof (2) is dissolved in a polar solvent, and preferably a halogen-basedsolvent such as chloroform, trichloroethane or tetrachloroethane, ordimethylformamide, dimethyl sulfoxide, dimethylacetamide or1-methyl-2-pyrrolidone to a concentration of 10 to 500 mg/100 ml, andpreferably 50 to 200 mg/100 ml to obtain a 1,4-di-substituteddiacetylene polymer solution.

(4-1) Photodegradation reaction of polydiacetylenes: A reaction vesselcontaining a polydiacetylene solution prepared in (3) is irradiated withlaser light at room temperature to carry out a photodegradation reactionof the polydiacetylene.

The reaction vessel is preferably a quartz or hard glass cell having anoptical path length of 10 to 100 mm, diameter of the light receivingsurface of 3.5 to 10.0 mm and volume of 0.1 to 1.0 ml, and in the caseof carrying out the reaction in large volume, a reaction vessel is usedthat is provided with a circulating flow cell or solution reservoirequipped with a stirrer. A pulse laser, and preferably awavelength-tunable femtosecond laser comprised of the combination of aregenerative amplifier and a parametric oscillator, is used for thelaser serving as the light source, and a beam expanding lens is used inthe case it is necessary to align the beam diameter with the diameter ofthe light receiving surface of the reaction vessel.

The light intensity at the light receiving surface is set to a specificintensity within the range of 10 to 350 mW with a dimming filter whilemeasuring with a power meter.

The present polymer can be obtained by setting the wavelength of theradiated laser light within the range of 250 to 1,200 nm. Degradation ofpolydiacetylenes is difficult to occur, if the wavelength is out of thisrange.

The wavelength region of 550 to 900 nm is transparent for single photonabsorption by polydiacetylenes, and the degradation reaction consideredto be caused by absorption of two photons proceeds uniformly in thedirection of the optical path within the reaction vessel, therebyfacilitating the formation of a mono-dispersed degradation producthaving an average degree of polymerization of 4 to 6 and decompositiondegree (Mw/Mn) within the range of 1.1 to 2.0.

In contrast, in the case of irradiation with laser light having awavelength region of 250 to 550 nm, the reaction occurs only near thelight receiving surface of the reaction vessel due to the strongabsorption of polydiacetylenes, thereby causing the reaction to becomenon-uniform in the direction of the optical path length, and causing atendency to be observed in which the composition of the reaction productis poly-dispersed instead of being mono-dispersed.

On the other hand, in the case of irradiation with laser light having awavelength band in excess of 900 nm, the degradation reaction proceedsmore slowly than in the case of a wavelength region of 550 to 900 nm,and a tendency is observed in which the dispersivity (Mw/Mn) becomesexcessively large.

Thus, the preferable wavelength region in the aforementioned method of(1) is 550 to 900 nm.

In the aforementioned method of (1), it is necessary for the radiationtime of the laser light that causes the photodegradation reaction of1,4-di-substituted diacetylene polymer to be set to within apredetermined range.

More specifically, the radiation time should be set while referring tothe intensity of the laser light, concentration of the polymer solution,volume of the reaction vessel, average degree of polymerization of thedesired polymer, namely the number average molecular weightcorresponding to said average degree of polymerization, and themeasurement results of gel permeation chromatography (GPC) correspondingto the molecular weight distribution.

However, in most cases, the radiation time is selected to be within therange of 10 seconds to 300 minutes (5 hours).

(4-2) Thermal Degradation Reaction of Polydiacetylenes: The presentpolymer can be obtained by placing a 1,4-di-substituted diacetylenepolymer solution prepared in (3) in a sealed glass tube or glass vesselwith stopper and causing thermal degradation by holding for 30 to 300minutes in a silicone oil bath heated to a temperature of 100° C. to300° C.

Measurement of the number average molecular weight corresponding to theaverage degree of polymerization and measurement of molecular weightdistribution of the present polymers obtained by the photodegradationreaction of (4-1) or the thermal degradation of (4-2) should be carriedout using a commercially available GPC measuring system (for example, aGPC measuring system manufactured by Hitachi, Ltd., column: GPC K-805 orGPC K-804 manufactured by Showa Denko).

More specifically, after measuring the weight average molecular weight(Mw) and number average molecular weight (Mn) of the polydiacetylenedegradation products based on a calibration curve as shown in FIG. 2prepared by GPC measurement of ten types of mono-dispersed polystyrenestandard samples having different molecular weights (Showa Denko), theaverage degree of polymerization is calculated by dividing the numberaverage molecular weight (Mn) by the molecular weight of the1,4-di-substituted diacetylene monomers, and then calculating themolecular weight distribution according to the ratio of Mw/Mn.

Normally, the measuring wavelength of the aforementioned GPC ispreferably 350 nm.

According to this measurement method, present polymer obtained by thephotodegradation reaction of (4-1) and present polymer obtained bythermal degradation according to (4-2) can both be confirmed to have anaverage degree of polymerization within the range of 4 to 200 and amolecular weight distribution within the range of 1.1 to 5.0.

In this manner, in the present polymers, together with controlling theaverage degree of polymerization to within a predetermined range,molecular weight distribution is also controlled to within apredetermined range. Consequently, in comparison with the case ofpolydiacetylenes of the prior art having an extremely large molecularweight and large molecular weight distribution, the present polymer canbe expected to demonstrate improved processability due to less deviationin its physical and chemical characteristics.

Similar to polydiacetylenes of the prior art, the present polymer hassuperior optical characteristics such as non-linear opticalsusceptibility, and has particularly superior transmittance.

The following provides an explanation of obtaining compositecompositions based on the present polymer and other materials.

Composite compositions consisting of the present polymer and othertransparent resins can be obtained by dissolving a present polymer in apolar solvent such as 1-methyl-2-pyrrolidone and mutually dissolvingwith a transparent resin such as an aromatic vinyl resin, acrylic resin,polyester, polycarbonate, polyurethane, polyamide, polysulfone,polycyclopentadiene, photosetting resin or thermosetting resin.

Similarly, composite compositions can be prepared by adding an inorganicpolymer, obtained in a polycondensation reaction of a metal alkoxidetypically represented by alkoxysilane, to the present polymer.

Although these compositions can be fabricated into films, sheets andthree-dimensional moldings, these moldings can be used as optical partsbased on their satisfactory optical transmittance, which is one of theproperties of the present polymers. Moreover, these compositions can beformed as a surface layer on other materials to obtain optical partsbased on their favorable optical transmittance.

Specific examples of optical parts using these composite compositionsinclude transparent substrates, microspherical resonators and opticalwaveguides.

Among the aforementioned optical parts, the formation of each of theaforementioned composite compositions in the form of a surface layer onglass or quartz transparent substrates or glass microspheres should becarried out by applying said composite composition by spin coating,dipping and so forth followed by curing by heating at a temperature of100° C. to 200° C.

EXPERIMENTAL EXAMPLES

The following provides an explanation of experimental examples verifyingthe formation of the present polymer based on each of the drawings.

Experimental Example 1

FIG. 3 shows a GPC chart of a decomposition product in the case ofirradiating a chloroform solution of a 1,4-di-substituted diacetylene [acompound represented by R—C≡C—C≡C—R′, wherein R and R′ represent(CH₂)₄OCONHCH₂COOC₂H₅, abbreviated as 4BCMU] polymer (abbreviated asPoly-4BCMU) with light having a wavelength of 775 nm and at an intensityof 40 mW using a wavelength-tunable femtosecond laser.

The vertical axis represents absorption at a wavelength of 350 nm, whilethe horizontal axis represents retention time.

Furthermore, retention time refers to the amount of time the samplemolecules are retained in the GPC column from the time of injection tothe time of detection, and is a function of the interaction with thenetwork structure of the gel filled into the column. Retention timebecomes shorter the larger the molecular weight, and the sample iseluted more slowly the smaller the molecular weight.

As shown in FIG. 4, the molecular weight of the 1,4-di-substituteddiacetylene polymer prior to photodegradation is within the range ofabout 10,000 to about 4 million, and average degree of polymerizationcovers a wide range of about 20 to 8,800, and the dispersivity of themolecular weight (Mw/Mn) also demonstrates a wide distribution of 9.50.

In looking at the dependency of molecular weight distribution onradiation time in the case of having irradiated this polymer solutionwith laser light at 775 nm, the degradation reaction of the1,4-di-substituted diacetylene polymer can be determined to not involvea sequential elimination reaction from the end of the polymer, butrather random scission of the polymer main chain. As a result, themolecular weight is ultimately reduced to 2,000 to 3,000, the averagedegree of polymerization is reduced to a narrow range of about 4 to 6,and the dispersivity of the molecular weight (Mw/Mn) demonstrates anarrow molecular weight distribution of 1.1 to 2.0, thereby indicatingthat the polymer has been decomposed into low molecular weight polymers,or oligomers.

This photodegradation reaction is dependent on light intensity, acharacteristic of the two-photon absorption process, and not only doesthe reaction accelerate with light intensity, but a tendency is alsoobserved in which the shape of the molecular weight distribution curveof the decomposition product is also affected by light intensity.

Thus, in order to obtain a diacetylene polymer or oligomer having atarget average degree of polymerization and molecular weightdistribution, it is imperative to select the wavelength, intensity andradiation time of the radiated laser light in consideration of theconcentration of the polymer solution and volume of the reaction vessel.

Experimental Example 2

A chloroform solution of Poly-4BCMU (concentration: 100 mg/100 ml) wasplaced in a quartz cell having a diameter of the light receiving surfaceof 3.5 mm and an optical path length of 10 mm, and after irradiating for1 minute at room temperature with light from a wavelength-tunablefemtosecond laser (wavelength: 775 nm, intensity: 300 mW), the molecularweight distribution of the reaction product were determined as shown inFIG. 5.

The ratio of Mw/Mn as calculated on the basis of a calibration curveprepared using mono-dispersed polystyrene standard samples is 1.55.

When the radiation time was increased to 10 minutes under the sameconditions for wavelength and intensity of the irradiated light, theratio of Mw/Mn representing molecular weight distribution becomes 1.19,indicating a narrow distribution, as shown in FIG. 6.

Since the number average molecular weight based on polystyrene is 2,248,the average degree of polymerization is able to be evaluated as 4.

Experimental Example 3

A chloroform solution of Poly-4BCMU (concentration: 100 mg/100 ml) wasirradiated for 60 minutes with light from a wavelength-tunablefemtosecond laser (wavelength: 800 nm, intensity: 15 mW) combining withthe use of a beam expanding lens using a quartz cell having a diameterof the light receiving surface of 8 mm and an optical path length of 10mm.

As a result of GPC measurement of the reaction product, since the numberaverage molecular weight (Mn) on the basis of polystyrene is 8,243, theaverage degree of polymerization is able to be evaluated as 16. Theratio of Mw/Mn that represents molecular weight distribution was 2.33 asshown in FIG. 7.

Experimental Example 4

A chloroform solution of Poly-4BCMU (concentration: 100 mg/100 ml) wasirradiated for 60 minutes with light from a wavelength-tunablefemtosecond laser (wavelength: 900 nm, intensity: 15 mW) combining theuse of a beam expanding lens using a quartz cell having a diameter ofthe light receiving surface of 8 mm and an optical path length of 10 mm.

According to the results of GPC measurement of the reaction product,since the number average molecular weight (Mn) on the basis ofpolystyrene is 12,350, the average degree of polymerization is able tobe evaluated as about 24. The ratio Mw/Mn that represents molecularweight distribution was 3.65 as shown in FIG. 8.

Experimental Example 5

The molecular weight distribution of the reaction product is shown inFIG. 9 in the case of placing a chloroform solution of Poly-4BCMU(concentration: 100 mg/100 ml) in a quartz cell having a diameter of thelight receiving surface of 3.5 mm and an optical path length of 10 mm,and irradiating for 10 minutes with light having a wavelength of 387.5nm in the single photon absorption region of polydiacetylene, using awavelength-tunable femtosecond laser.

As is clear from FIG. 9, although the molecular weight of the reactionproduct is 5,000 or less in the case the irradiated light has awavelength of 387.5 nm in the single photon absorption region, it isshown that there are cases in which substances having a low molecularweight of 1,000 or lower are contained in a portion thereof.

However, the formation of such a reaction product having a molecularweight of 1,000 or lower can be avoided as much as possible by settingthe intensity and radiation time of the irradiated light equal to orless than constant values.

Experimental Example 6

1-methyl-2-pyrrolidone solutions of Poly-4BCMU (concentration: 100mg/100 ml) were placed in glass vessels with stoppers and held at atemperature of 150° C. for 30 minutes and 60 minutes followed bydetermination of the molecular weight distributions of the reactionproducts as shown in FIGS. 10 and 11.

Since the number average molecular weight (Mn) of the reaction product30 minutes after reaction is 20,700, the average degree ofpolymerization can be evaluated as 48 and the ratio of Mw/Mn thatrepresents molecular weight distribution is 4.11. Since the numberaverage molecular weight (Mn) of the reaction product after 60 minutesis 6,649, the average degree of polymerization can be evaluated as 14,and the ratio of Mw/Mn that represents molecular weight distribution was1.58.

All of the aforementioned Experimental Examples 1 to 6 were carried outon Poly-4BCMU.

However, since the average degree of polymerization is affected by thestrength of the carbon bonds that form the main chain even in the caseof using other substituents for organic group substituents R and R′ ofthe present polymer, experimental values similar to the case ofPoly-4BCMU are expected to be obtained, and this generally applies inthe same manner to the ratio Mw/Mn that represents molecular weightdistribution.

Experimental Example 7

The present polymer obtained according to the aforementioned method (1)or (2) was dissolved in a polar solvent such as 1-methyl-2-pyrrolidonefollowed by preparing composite compositions by mutually melting with atransparent resin such as polystyrene, polymethyl methacrylate orpolycarbonate, or by adding an inorganic polymer obtained by apolycondensation reaction of a metal alkoxide typically represented byalkoxysilane.

As a result of coating these compositions onto a glass substrate,heating for 60 minutes at 100° C. and observing the cured film with anoptical microscope, the present polymer produced by the photodegradationreaction of (1) or the thermal degradation of (2) were confirmed todemonstrate satisfactory compatibility with the transparent resin ormatrix materials such as the inorganic polymer obtained by apolycondensation reaction of alkoxysilane.

Experimental Example 8

A uniformly coated surface was obtained as a result of coating thecomposite composition with a matrix material produced in ExperimentalExample 7 onto a transparent substrate made of glass, quartz and soforth or the surface of glass microspheres by spin coating, dipping andso forth.

The surface layer resulting from the aforementioned composition wasconfirmed to demonstrate satisfactory transmittance overall.

INDUSTRIAL APPLICABILITY

The present invention makes it possible for the first time to preparethe present polymer by photodecomposition or thermal decomposition inwhich number average molecular weight, and even average degree ofpolymerization based on said number average molecular weight, arecontrolled within a predetermined range, and in which molecular weightdistribution is also controlled within a predetermined range, thepreparation of which by a polymerization reaction was previouslyconsidered to be impossible.

Although the present polymer according to the present inventionconstitutes a novel group of substances, the present polymer can beexpected to demonstrate superior processability by controlling theaverage degree of polymerization and molecular weight distribution towithin predetermined ranges, while also having superior opticalcharacteristics such as non-linear optical susceptibility andparticularly superior transparency similar to previous high molecularweight 1,4-di-substituted diacetylene polymers.

Consequently, the present polymers along with the aforementionedcomposite compositions in which they are used can be expected todemonstrate usefulness in a wide range of fields including electronics,optoelectronics and photonics.

1-12. (canceled)
 13. A 1,4-diacetylene polymer that is soluble in anorganic solvent, composed of a repeating unit represented by the generalformula ═CR—C≡C—CR′═ (wherein R and R′ represent identical or differentmonovalent organic substituents), and has an average degree ofpolymerization of 4 to 200 and a ratio (Mw/Mn) of weight averagemolecular weight (Mw) to number average molecular weight correspondingto said average degree of polymerization (Mn) of 1.1 to 5.0; wherein,the organic substituents R and R′ are selected from:(CH₂)_(m)OCONHCH₂COOC_(n)H_(2n+1) (wherein m represents an integerwithin the range of 3 to 6, and n represents an integer within the rangeof 1 to 10), (CH₂)_(m)CONHCH₂COOC_(n)H_(2n+1) (wherein m represents aninteger within the range of 3 to 6, and n represents an integer withinthe range of 1 to 10), (CH₂)_(m)OSO₂C₆H₄CH₃ (wherein m represents aninteger within the range of 3 to 6), and(CH₂)_(n)OCONHCH₂CONHC_(n)H_(2n+1) (wherein m represents an integerwithin the range of 3 to 6, and n represents an integer within the rangeof 1 to 10).
 14. A process for producing the 1,4-di-substituteddiacetylene polymer as claimed in claim 13, further comprising the stepof irradiating a solution of soluble 1,4-di-substituted diacetylenepolymer with laser light having a wavelength within the range of 250 to1,200 nm, to cause a photodegradation reaction of said polymer.
 15. Aprocess for producing a 1,4-di-substituted diacetylene polymer asclaimed in claim 14, wherein the irradiation time is from 10 seconds to180 minutes.
 16. A process for producing the 1,4-di-substituteddiacetylene polymer as claimed in claim 13, further comprising the stepof heating a solution of soluble 1,4-di-substituted diacetylene polymerto a temperature of 100 to 300° C. to cause thermal degradation of saidpolymer.
 17. A process for producing a 1,4-di-substituted diacetylenepolymer as claimed in claim 16, wherein the heating time is from 30minutes to 5 hours.
 18. A composite composition in which the1,4-di-substituted diacetylene polymer as claimed in claim 13 iscompatible with a transparent sheet.
 19. The composite composition asclaimed in claim 18, wherein the transparent sheet is selected from thegroup consisting of an aromatic vinyl resin, acrylic resin, polyester,polycarbonate, polyurethane, polyamide, polysulfone,polycyclopentadiene, photosetting resin and thermosetting resin.
 20. Acomposite composition with an inorganic polymer obtained by reacting the1,4-di-substituted diacetylene polymer as claimed in claim 13 in apolycondensation reaction with a metal alkoxide represented byalkoxysilane.
 21. An optical part obtained by using one of a film, sheetand three-dimensional molding based on the compositions as claimed inclaim 20 and in which the 1,4-di-substituted diacetylene polymer iscompatible with a transparent sheet.
 22. An optical part obtained byusing the composite compositions as claimed in claim 16 as a surfacelayer and in which the 1,4-di-substituted diacetylene polymer iscompatible with a transparent sheet.
 23. The optical part according toclaim 22, wherein the composite compositions are used in transparentsheets, microspherical resonators and optical waveguides.
 24. A processfor producing the 1,4-di-substituted diacetylene polymer as claimed inclaim 14, wherein the laser light has a wavelength within the range of550 to 900 nm.